Anumber of ladies in summer dresses and gentlemen ingrey frock-coats and tall hats stood on the lawn or satupon the benches;
一群身着夏装的女士和穿灰色长礼服、戴高礼帽的绅士或站在草坪上，或坐在长凳上；
2
Anumber of studies has shown that some bio-chemical processes can be activated by ultra-sound in the presence of enzymes and cells.
许多研究发现，在有酶或细胞参与的情况下，一些过程可在超声作用下被激活。
3
It is an evidence-based, nondrug, short-term (usually four to eightsessions) therapy based on the concept that chronic insomnia is maintained by anumber of physical and behavioral factors.